Piano sounding-board.



T. F. O'SHAUGHNESSY.

PIANO SOUNDING BOARD.

APPLICATION FILED AUG.20,1917.

Patented Dec. 17, 1918.

2 SHEETS-SHEET 1- QQ F Q INVENTOR y amaj v fiagmevy T. F. OS HAUGHNESSY. PIANO SOUNDING BOARD. APPLICATION FILED.AUG.20, x911.

atented Dec. 17, 1918.

2 SHEETS-SHEET 2- To all whom it may ments in Piano THOMAS E. OSHAUG-HNESSY,

caries,

OF NEW YORK, N. Y.

. PIANO SOUNDING-BOA'RD.

Application concern: 1

Be it known that I, THOMAS F. OSnAueir- NESSY, a citizen of the United States, and resident of New York, in the county of Bronx and State of New York, have in-' vented certain new and useful Improve- Sounding-Boards, of which the following is a specification.

' This invention relates to double sounding boards forpianos.

It is necessary that the sounding board respond to all tones throughout the compass of the instrument to produce brilliancy and quality. Heretofore these results have not been attained to a desirable degree.

The main object of my invention, therefore, is to improve the quality of tone of stringed instruments.

Another object of vide a sounding board adapted to produce betterresults than heretofore has been the case.

Generally speaking these and other objects are accomplished by providing a double sounding board the air volume "of which may be varied, and means for varying the air volume. y

The invention is illustrated on the ac coinpanying sheets of drawings, in which,

Figure 1 is a plan view of a sounding board embodying my invention and shown in association with an equipment of bridges, strings and-hammers;

Fig. 2 is a sectional view plane of line 22 of Fig. 1;

Fig. 3 is a rear elevation of the sounding board, a portion of the back being broken away to show a part of the internal construction;

Fig. 4 is an enlarged detail sectional view of a sounding post forming a part of invention.

The various novel features of my invention will be apparent from the followiug description and drawings and will be part ed larly pointed out in the appended claims.

Referring particularly to the drawings, it will be seen that I have provided a piano sounding board 10 mounted in a suitable support 9. Mounted upon one surface of the sounding board are suitable bridges'll and 12, across which are strung suitable strings 13. In this case the strings are arranged to be struck by hammers 14 for setting the strings in vibration.

The sounding board comprises a hollow taken in the the invention is to pro- Specification of Letters Patent.

, through the back creased amount, or in other Patented Dec. 1%, 1918,

filed August 20, 1917. Serial No. 187,100.

box completely closed at the margins and having a top 15, preferably of spruce wood, and a back 16, preferably of maple wood. The top 15 and back 16 are substantially parallel to and spaced from each other by a rim member 17 whereby an air chamber 18 is formed. Arranged on opposite sides of the bridge 11 are F openings 19 which are arranged in pairs. pair are alike in size, and the size of the openings'of the pairs differs along the length of the bridge. The number of openings may be increased or decreased accord .ig to the size of the board. The forms of iese open-- openings ings may be varied. The large are arranged at the base end of the instrument, and the small openings are arranged at the treble end of the instrument, the intermediate ones being properly graduated. Strips 20, preferably of maple, are arrangedon the under side of the top 15 for cooperation with sound posts to be mentioned later. Likewise strips 21 of the same character, which like the other strips 20 run longitudinally of the box, are mounted on the inside of the back 16. l have provided sound posts 22 which are preferably in the form of bolts and which are threaded 16 and through the strips 21 and bear against the under side of the strips 20 secured to the under side of the top 15. The sound posts are adjustable lengthwise, are earriedby the back and operatively press against the top 15 or sounding board proper. if the screw sound posts are screwed into the box to a greater extent than shown in Fig. 2, the top 15 and back 16 will be separatedfroin each other an inmay cc dethe screw sound volume of the box will be incre. wise the air volume of'the be creased by withdrawing posts a given amount.

By use of the sound posts 22 and their associated parts l have improved the quality of tone. When the sound posts have been adjusted to the desired positions for accomplishing the desired results said sound posts are locked in such positions by lock nuts 23, which are mounted on the sound osts and engage with the under side of the back 16 of the box. These sound posts 22, which are adjustable from the outside of the box. are arranged under the bridges 11 and 12 and not only sustain the pressure of the strings on the bridges, but

being made in The l openings of each word the air r the form of Wooden screws or bolts vary the stress of the top and back of the box. These sound posts also are effective in increasing or decreasing the air volume of the sounding board to unify the pitch of the same with the pitch of the strings.

fBy means of my sounding board, including the adjustable sound posts, all of the tones throughout the Whole compass of the instrument will be properly responded to, the sound waves occasioned by vibration of the strings thereby producing tones of 'brilliancy and improved quality.

It is. evident that there may be various modifications of the invention herein particularly shown and described, and it is my intention to cover all such modifications which do not involve a departure from the spirit and scope of the invention as set forth 'in the following claims.

I claim:

1. A piano sounding board comprising a hollow box completely closed at the margins and having a sounding board and a back substantially parallel thereto, a bridge on said sounding board, and a sound post adjustable lengthwise through thee-back, said sound post carried by said back and operatively pressing against the soundin board for varying the volume of the sounding box,

the sounding board being ribleSs and having a plurality of openings arranged in proximity to said bridge.

'2. A piano sounding board comprising a hollow box completely closed at the margins and having a sounding board and a back substantially parallel thereto, and a sound post adjustable lengthwise through the back, said sound post carried by said back and operatively pressing against the sounding board for varying the volume of the sounding box, the soundin board being ribless and having a plurality of openings, the soundpost being adjustable from outside the box.

Signed at the city of New York, Bronx 00., State of New York, this 13th day of August, A. D. 1917.

THOMAS F. OSHAUGHNESSY.- 

